Python：特定單詞后的文本文件中的換行符

Question

我有一個文本文件，只有一行有10.000個單詞。 現在我想在特定單詞（“Comment”）出現之前添加換行符，我還想在新的文本文件中寫這個：

文本文件看起來像：“評論：是的，你是對的評論：這是非常有趣的評論：真的嗎？

新文件應如下所示：

    Comment: Yeah, you're right
    Comment: That's very interesting
    Comment: really?

我在下面嘗試了這個代碼，但是出了點問題。 我是初學者，到現在為止，我無法找到解決方案。 謝謝你的幫助

    -*- coding: utf-8 -*-

    d = file('test.txt','r')
    text=d.read()
    e = file('output.txt','w')
    x=raw_input("Insert word:")
    # -> Comment
    for line in d.readlines():
          if line.startswith(x):
            word.append(+"\n")
            e.write()
            e.close()
            d.close()

Answer 1

你只需要使用str.replace：

e.write(d.read().replace(' Comment:', '\nComment:'))

Answer 2

以下是對錯誤的解釋：

d = file('test.txt','r')
text=d.read() # Ok: now 'text' contains the entire file contents.
e = file('output.txt','w')
x=raw_input("Insert word:")
# -> Comment
for line in d.readlines(): # You already read the whole file, so
# this loop can't read any more. But even without that, your input
# file only contains one line, so this would only loop once.
      if line.startswith(x): # You are trying to look for a word at the
      # beginning of each line, in order to determine where to put the
      # line breaks. But the words can't be found at the beginnings of
      # all the lines until those lines exist, i.e. after the line 
      # breaks have been positioned.
        word.append(+"\n") # This makes no sense at all. You can't 
        # '.append' to 'word' because there is no 'word' defined yet,
        # and '+"\n"' is trying to treat a string like a number. Yes,
        # you can use '+' to join two strings, but then you need one
        # on either side of the '+'. 1 + 1, "hi " + "mom".
        e.write() # If you want to write something to the file, you have
        # to specify what should be written.
        e.close() # If the loop *did* actually execute multiple times,
        d.close() # then you definitely wouldn't want to close the files
        # until after the loop is done.

其他答案解釋了如何正確解決問題。 我們將文件讀入一個字符串，並在每個單詞出現之前添加一個換行符。 這相當於用（換行符，后跟單詞）替換單詞的每個外觀。 該功能是內置的。 然后我們將修改后的字符串寫入輸出文件。

Answer 3

一個非常簡單的解決方案是：

for line in d.readlines():
    e.write(line.replace("Comment:",  "\nComment:"))

e.close()    

Answer 4

你可以做'\\n'.join(x+': '+string for string in line.split(x+': '))